Of course, jurors are not supposed to assume that someone else will somehow sort out the mess they're presented with when a case is appealed. In fact, the law is supposed to make jurors feel a huge weight of moral responsibility for these life or death decisions. No doubt, many jurors do. When they don't, however, the result can be catastrophic as the Cruz case suggests. Why they don't assume responsibility may be explained, in part, by one of the classic experiments in social psychology.

Sound from an old audio recording: "Let me out of here. You have no right to keep me here. Let me out. Let me out. Let me out."

In 1961, Stanley Milgram, an assistant professor of psychology at Yale University,
conducted what have become known as the "Obedience Experiments." Milgram persuaded ordinary people to give painful electric shocks to people they had only just met.

The subjects, known as "teachers" were told to increase the strength of an electric shock given a so-called "learner" each time he made a mistake in memorizing a series of word pairs. The subjects believed they were part of a study to ascertain whether negative reinforcement could motivate learning. In reality, Milgram wanted to test whether ordinary people would obey an authority figure even to the point of being sadistic and cruel. To make the experiment even more provocative, the "teachers" were led to believe that the "learner" they were shocking had a heart condition.

Sounds from the Milgram experiment: A buzzer.
Learner: "Ohh! I can't stand the pain, let me out of here."
Teacher: "He can't stand it. I'm not going to kill that man in there. You hear him hollering. What if something happens to him?"

In reality, the "learner" was not being shocked, and was deliberately giving wrong answers. But the subject or "teacher" didn't know this. Eventually the "learner" with his heart condition would stop screaming or banging on the wall and fall silent, leading the "teacher" to believe he'd lost consciousness.

Sounds from the Milgram experiment:
Teacher: "Something's happened to that man in there. You better check in on him, sir. He won't answer me or nothing."
Experimenter (Authority figure): "Please continue. Go on please."
Teacher: "You accept all the responsibility?"
Experimenter: "The responsibility is mine, correct. Please go on."

Although the "teacher" was clearly uncomfortable giving the electric shocks, goaded by the experimenter and assured that he was not personally responsible, the teacher eventually gave the unconscious "learner" more than 400 volts. In fact, half of the subjects in Milgram's experiment administered the maximum punishment. Nearly all the subjects gave the maximum voltageif they were part of a group, and led to believe that they were simply going along with a majority or unanimous decision.